Cutting a workpiece such as building materials like lumber, metal, pvc stock and siding etc., with a power saw typically requires the initial step of positioning the workpiece in a desired configuration with respect to the saw to obtain a desired length of the workpiece. A positioning means is especially important when cutting a workpiece to a specific length or width especially where numerous work pieces must be cut to the same length an accurate stable positioning means can allow the operator to efficiently cut numerous workpieces to the same length. When using a power saw it is inaccurate and inefficient to measure the length of each workpiece and then mark the length with a pencil. Also, if several cuts are going to be made at the same length, it is inefficient to measure, mark and re-measure every time you make a cut. It is common to use workbenches with cutting and measuring guides that aid in making accurate cuts. To this end, several different types of guide means have been created which arrange a workpiece in such a desired configuration for cutting by a power saw.
As an example of prior art, a complex lumber measurement device is shown is shown in U.S. Pat. No. 2,747,625 to Small. This device functions well to measure a particular cutoff length, but is expensive and designed more for wood shops or high volume commercial shops and would not be affordable to a typical owner of a power saw.
A number of prior art devices utilize the concept of a slide which is lockable to a fence of the radial arm saw (that is, the upright along which a board is positioned prior to cutting). Such devices are shown in U.S. Pat. No. 4,256,000 to Siedel and U.S. Pat. No. 4,111,088 to Ziegelmeyer. While such device often function adequately, they must be removed from the rail in order to allow the saw to be placed in a mode where boards of varying lengths can be easily cut.
One prior art device has been able to partially overcome the problem of quickly moving the positioner out of the way and is shown in the U.S. Pat. No. 4,412,468 to Bucy. In Bucy, a fixed slide guide is position along the back of the fence with a slide that can be rotated to extend forward of the fence. The fence is channeled to allow the guide to fall into a selected channel. While the slide in the Bucy '468 device can be moved to various locations and can be moved out of the path of boards to be cut when different lengths are desired, the fixed spacing between channels prevents easy position of the slide in an infinitely large variety of positions and prevents simple sliding of the slide in a down position to a new location.
U.S. Pat. No. 4,972,949 to Grove discloses a radial arm saw including a calibrated fence having a plurality of stop gauge members that are slidably mounted in fence units. The design of Grove '949 does not allow for small increments of stop distance and therefore is limited in its precision. Also, the stop gauge members are spring-loaded and therefore are prone to wear and failure.
The above references provide significant difficulty and inefficiency when sawing a plurality of boards, panels and the like at one time. The stop member has to be unscrewed, positioned anew and re-tightened for each cutting sample. Employing the existing technology, therefore increases the accuracy and efficiency of standard table saw cutting relative to the previous technology.